Drafting instrument.



D J. KELSEY.

DRAI'TING INSTRUMENT. APPLICATION mam nno.14,'1eos.

Patented Aug. 9, 1910.

WITNESSES.- CL, 76

at: NORRIS IZTERS 9" wnsmrlarord, n, 1:.

DUANE J. KELSEY, OF NEW HAVEN, CONNECTICUT.

DRAFTING- INSTRUMENT.

Specification of Letters Patent.

Patented Aug. 9, 1910.

Application filed December 14, 1908. Serial No. 467,568.

To all whom it may concern:

Be it known that I, DUANE J. KnLsnY, a

. citizen of the United States, residing at New Haven, in the county ofNew Haven and State of Connecticut, have invented a new and usefulDraftingInstrument, of which the following is a specification.

My invention relates to improvements in drafting instruments in which anerasing shield is combined with a ruling form and a lineal scale and theobject of my invention is to provide an erasing shield, conjoined to aruling form and a lineal scale in a way to facilitate the operations oferasing, ruling and scaling, by bringing the control of these differentinstruments under one piece. I attain this object by the deviceillustrated in. the accompanying drawings in which Figure 1 is a topview of the instrument and Fig. 2 is a section on the line 1, 2, of Fig.1.

In Fig. 1 the plate at having various depressions with thin edgedopenings as at b, b, to admit the action of an eraser, is at tached tothe ruling form 6 by means of the knob nut 7' upon its upper side and ascrew from beneath, which serves to clamp together the ruling form c andthe erasing plate a, the latter being further prevented from turningaround by the hooked end g entering a hole in the ruling form 0 at h.The plate a has an offset at i that its under side may lie inapproximately the same plane as the lower side of the ruling form 6. Theplate 6; also has spring clips at c c to receive lineal scales (Z ofvarious graduations. The clips 0 c are formed by bending over proper mgto permit the removal and projections on the blank from which the platea is formed, so as to be slightly yieldinterchange of differentlygraduated scales. The scales 0? have the front edge bent down to makeaccurate measurements more feasible.

Although erasing plates and lineal scales of the general form shown maybe attached to ruling forms of various shapes they are particularlyadapted to the ruling form shown, in that a compact device of wideapplication is thus secured, as it supplies an erasing plate, a scaleand a ruling form that gives ruling edges at all the slopes of both the45 and 60 triangles commonly used by draftsmen and at the same timepermits easy control of all by a knob.

I am aware that prior to my invention erasing grooves and lineal scaleshave each been used in connection with ruling forms. I therefore do notclaim such a combination broadly.

I claim-- 1. The combination with a ruling form of a shield mounted. onsaid form and a lineal scale detachably secured to the outer edge ofsaid shield.

2. The combination with a ruling form of an erasing shield mounted onsaid form and projecting beyond one edge thereof, said shield providedwith a thin edged opening and with clips at its outer edge and a linealscale engaged by said clips.

DUANE J. KELSEY.

Vitnesses A. BEVERLY STEVENS, FRANK MINER.

